[Federal Register: January 27, 2005 (Volume 70, Number 17)]
[Rules and Regulations]
[Page 3867-3871]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27ja05-5]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-80-AD; Amendment 39-13948; AD 2005-02-03]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A,
-217C, and -219 Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding an existing airworthiness directive
(AD) for Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219
series turbofan engines. That AD currently requires torque inspection
of the 3rd stage and 4th stage low pressure turbine (LPT) blades for
shroud notch wear and replacement of the blade if wear limits are
exceeded. This AD continues to require those torque inspections at
shorter inspection intervals of the refurbished 3rd stage and 4th stage
LPT blades, but the same or longer inspection intervals of the new 3rd
stage and 4th stage LPT blades, for shroud notch wear and replacement
of the blade if wear limits are exceeded. This AD also requires
replacing LPT-to-exhaust case bolts and nuts with bolts and nuts made
of Tinidur material. This AD results from reports of 194 blade
fractures since 1991, with 37 of those blade fractures resulting in LPT
case separation, and three reports of uncontained 3rd stage and 4th
stage LPT blade failures with cowl penetration. We are issuing this AD
to prevent an uncontained blade failure that could result in damage to
the airplane.
DATES: This AD becomes effective March 3, 2005. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of March 3, 2005.
ADDRESSES: You can get the service information identified in this AD
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone
(860) 565-8770, fax (860) 565-4503.
You may examine the AD docket at the FAA, New England Region,
Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA. You may examine the service information, at the FAA,
New England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA; or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
FOR FURTHER INFORMATION CONTACT: Keith Lardie, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7189, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with a proposed airworthiness directive (AD). The proposed AD applies
to Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series
turbofan engines. We published the proposed AD in the Federal Register
on August 16, 2004 (69 FR 50346). That action proposed to require
torque inspections of the 3rd stage and 4th stage LPT blades for shroud
notch wear and replacement of the blade if wear limits are exceeded.
That action also proposed to require replacing the LPT-to-exhaust case
bolts and nuts with bolts and nuts made of Tinidur material.
Examining the AD Docket
You may examine the AD Docket (including any comments and service
information), by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. See ADDRESSES for the
location.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Use of Radioisotope Inspection Procedure
One commenter proposes to use a radioisotope inspection procedure,
which they have developed and was approved as an alternative method of
compliance (AMOC) for a previously issued AD. The commenter states that
this inspection method is more reliable than the torque inspections
mandated in this AD and provides an equivalent level of safety. The FAA
does not agree. The commenter did not provide data to substantiate the
claim of an equivalent level of safety as it relates to the revised
inspection intervals. The commenter's proposal is also operator-
specific and does not provide literature for the rest of the fleet. The
FAA will evaluate a request for an AMOC that includes data
substantiating that an acceptable level of safety is maintained using
this procedure.
Costs of Compliance Underestimated
Another commenter states that the costs of compliance are
underestimated. The commenter requests that we consider the costs of
numerous parts removed when complying with this AD. The FAA does not
agree. The indirect costs associated with this AD are not directly
related to the required actions, and therefore, are not addressed in
the economic analysis for this AD. A finding that an AD is warranted
means that the original engine design no longer achieves the level of
safety specified by related airworthiness requirements and that other
required actions are necessary.
Another commenter states that the costs of compliance are
underestimated. The commenter states that the cost of turbine blades
and cost of labor to replace the blades when complying with this AD
should be considered. The FAA agrees. We estimate that 10% of the blade
sets will fail the inspection per year and will require replacement.
Therefore, the estimated cost of turbine blades and labor to replace
the blades is added to the total cost of the AD to U.S. operators to
perform initial torque inspection and bolt and nut replacement.
Request To Clearly Identify the Superseded AD
Another commenter requests that the identification of the
superseded AD be clarified. The FAA does not agree. The fact that this
AD supersedes AD 99-27-01 is clearly stated in the compliance section
of this AD. Although AD 99-22-14 requires replacement of the LPT-to-
exhaust case bolts and nuts, that AD primarily addresses installation
of high pressure turbine (HPT) containment hardware. Further, a notice
of proposed rulemaking was published in the Federal Register on July
15, 2004 (69 FR 42356), which moves the requirement to replace the LPT-
to-exhaust case bolts and nuts from AD 99-22-14 to this AD.
Request To Include Reference to NDIP-662, Revision D
Another commenter requests that this AD include a reference to
NDIP-622, Revision D. The FAA does not agree. We assume that the
commenter intended to
[[Page 3868]]
say NDIP-662, Revision D and not NDIP-622, Revision D. This AD already
references PW ASB No. JT8D A6224, Revision 5, which specifies the use
of NDIP-662, which is included as an Appendix in the ASB. Because all
pages of NDIP-662, Revision D, are included in the ASB, a clarification
to the reference and a change to this AD are not necessary.
Request To Define ``Accessibility to the LPT-to-Exhaust Case Bolts''
Another commenter requests that this AD include a definition of the
statement ``accessibility to the LPT-to-exhaust case bolts'' and that
the definition match the one provided in PW SB 6455. The FAA agrees. A
definition of ``accessibility to the LPT-to-exhaust case bolts'' is
included in this AD.
Overlap Between Inspection Torque Readings
Another commenter states that there is an overlap between the
inspection torque readings in the tables providing the repetitive
torque inspection intervals. For example, one range in Table 3 states
``* * * but greater than or equal to 10 LB-IN (1.130 N.m).'' Another
range in Table 3 states ``Less than or equal to 10 LB-IN (1.130 N.m) *
* *''. A single value cannot have two different requirements. The FAA
agrees. The affected tables are corrected in this AD.
Inspect Only Turbine Blades That Fail Inspection
Another commenter proposes to inspect only the turbine blades of
the LPT stage that fails the torque check inspection. Also, the
commenter proposes that the requirement to inspect the turbine blades
of the other LPT stages should be suggested rather than mandated as
proposed in the AD. The FAA agrees. This AD clarifies the information
about how to return an engine to service. In addition, this AD
clarifies the information about how the repetitive inspection intervals
may be reset.
Conclusion
We have carefully reviewed the available data, including the
comments received, and determined that air safety and the public
interest require adopting the AD with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
There are about 2,345 PW JT8D-200 series turbofan engines of the
affected design in the worldwide fleet. We estimate that 1,143 engines
installed on airplanes of U.S. registry are affected by this AD. We
also estimate that it will take about 1 work hour per engine to perform
the torque inspection and 1 work hour per engine to perform the bolt
and nut replacements. The average labor rate is $65 per work hour. It
is estimated that 10% of the blade sets will fail the inspection per
year and will require replacement. The average cost for a new blade set
is $72,500. The new blades take about 23 work hours to install. Based
on these figures, the annual replacement cost of the AD to U.S.
operators is $8,584,020. The required bolts and nuts will cost about
$1,734 per engine. Based on these figures, we estimate the total annual
cost of this AD to U.S. operators to perform initial torque inspection
and bolt and nut replacement to be $10,565,982.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
subtitle VII, part A, subpart III, section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the National Government and the States, or on the distribution of power
and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a summary of the costs to comply with this AD and
placed it in the AD Docket. You may get a copy of this summary by
sending a request to us at the address listed under ADDRESSES. Include
``AD Docket No. 98-ANE-80-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the Federal Aviation Administration amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by removing Amendment 39-11482 (64 FR
72916, December 29, 1999) and by adding a new airworthiness directive,
Amendment 39-13948, to read as follows:
2005-02-03 Pratt & Whitney: Amendment 39-13948. Docket No. 98-ANE-
80-AD. Supersedes AD 99-27-01, Amendment 39-11482.
Effective Date
(a) This AD becomes effective March 3, 2005.
Affected ADs
(b) This AD supersedes AD 99-27-01.
Applicability
(c) This AD applies to Pratt & Whitney (PW) JT8D-209, -217, -
217A, -217C, and -219 series turbofan engines. These engines are
installed on, but not limited to, Boeing 727 series and McDonnell
Douglas MD-80 series airplanes.
Unsafe Condition
(d) This AD results from reports of 194 blade fractures since
1991, with 37 of those blade fractures resulting in low pressure
turbine (LPT) case separation, and three reports of uncontained 3rd
stage and 4th stage LPT blade failures with cowl penetration. We are
issuing this AD to prevent an uncontained blade failure that could
result in damage to the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
[[Page 3869]]
Initial Torque Inspection for JT8D-209, -217, and -217A Engines
(f) For JT8D-209, -217, and -217A engines, perform the initial
torque inspection of 3rd and 4th stage LPT blades for shroud notch
wear. Use the procedures described in Accomplishment Instructions,
part 1, paragraphs 1. through 3. of PW Alert Service Bulletin (ASB)
No. JT8D A6224, Revision 5, dated June 11, 2004, at the applicable
threshold in the following Table 1:
Table 1.--Initial Torque Inspection Threshold for JT8D-209, -217, and -217A Engines
----------------------------------------------------------------------------------------------------------------
Blade type Hours time-in-service (TIS) Inspection threshold
----------------------------------------------------------------------------------------------------------------
(1) New pre-Service Bulletin (SB) No. Any number................................. Within 6,000 hours TIS.
5867 (small notch) 3rd stage turbine
blades.
(2) Refurbished pre-SB No. 5867 (i) Fewer than 3,000....................... Within 4,000 hours TIS.
(small notch) 3rd stage turbine
blades.
(ii) 3,000 or more......................... Within 6,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
(3) New post-SB No. 5867 (large Any number................................. Within 10,000 hours TIS.
notch) 3rd stage turbine blades.
(4) Refurbished post-SB No. 5867 (i) Fewer than 6,000....................... Within 7,000 hours TIS.
(large notch) 3rd stage turbine
blades.
(ii) 6,000 or more......................... Within 8,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
(5) New pre-SB No. 6029 (small notch) Any number................................. Within 6,000 hours TIS.
4th stage turbine blades.
(6) Refurbished pre-SB No. 6029 (i) Fewer than 3,000....................... Within 4,000 hours TIS.
(small notch) 4th stage turbine
blades.
(ii) 3,000 or more......................... Within 6,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
(7) New post-SB No. 6029 or new post- Any number................................. Within 10,000 hours TIS
SB No. 6308 (large notch) 4th stage
turbine blades.
(8) Refurbished post-SB No. 6029 or (i) Fewer than 6,000....................... Within 7,000 hours TIS.
refurbished post-SB No. 6308 (large
notch) 4th stage turbine blades.
(ii) 6,000 or more......................... Within 8,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
----------------------------------------------------------------------------------------------------------------
Repetitive Torque Inspections for JT8D-209, -217, and -217A Engines
(g) For JT8D-209, -217, and -217A engines, perform repetitive
torque inspections of 3rd and 4th stage LPT blades for shroud notch
wear. Use the procedures described in Accomplishment Instructions,
Part 1, Paragraph 1. of PW ASB No. JT8D A6224, Revision 5, dated
June 11, 2004, at the applicable intervals in the following Table 2
and Table 3:
Table 2.--3rd Stage Repetitive Torque Inspection Intervals for JT8D-209, -217, and -217A Engines
----------------------------------------------------------------------------------------------------------------
Inspection torque readings Number of readings Disposition
----------------------------------------------------------------------------------------------------------------
Greater than or equal to 15 LB-IN All........................................ Repeat torque inspection
(1.695 N.m). within 1,000 hours TIS
since last inspection.
Less than 15 LB-IN (1.695 N.m) but One or more................................ Repeat torque inspection
greater than or equal to 10 LB-IN within 500 hours TIS since
(1.130 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but One to three............................... Repeat torque inspection
greater than or equal to 5 LB-IN within 125 hours TIS since
(0.565 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but Four or more............................... Remove engine from service
greater than or equal to 5 LB-IN within 20 hours TIS since
(0.565 N.m). last inspection.
Less than 5 LB-IN (0.565 N.m)........ One or more................................ Remove engine from service
within 20 hours TIS since
last inspection.
----------------------------------------------------------------------------------------------------------------
Table 3.--4th Stage Repetitive Torque Inspection Intervals for JT8D-209, -217, and -217A Engines
----------------------------------------------------------------------------------------------------------------
Inspection torque readings Number of readings Disposition
----------------------------------------------------------------------------------------------------------------
Greater than or equal to 15 LB-IN All........................................ Repeat torque inspection
(1.695 N.m). within 1,000 hours TIS
since last inspection.
Less than 15 LB-IN (1.695 N.m) but One or more................................ Repeat torque inspection
greater than or equal to 10 LB-IN within 500 hours TIS since
(1.130 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but One to six................................. Repeat torque inspection
greater than or equal to 5 LB-IN within 125 hours TIS since
(0.565 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but Seven or more.............................. Remove engine from service
greater than or equal to 5 LB-IN within 20 hours TIS since
(0.565 N.m). last inspection.
Less than 5 LB-IN (0.565 N.m)........ One or more................................ Remove engine from service
within 20 hours TIS since
last inspection.
----------------------------------------------------------------------------------------------------------------
[[Page 3870]]
(h) Subsequent repeat inspection intervals must not exceed the
previous inspection interval.
JT8D-209, -217, and -217A Engines Removed From Service
(i) JT8D-209, -217, and -217A engines removed from service may
be returned to service after a detailed inspection and repair or
replacement for all blades, of the failed stage, that exceed Engine
Manual limits is done. Information on repairing or replacing turbine
blades can be found in Sections 72-53-12 through 72-53-13 of the
JT8D-200 Engine Manual, Part No. 773128.
Initial Inspection for JT8D-217C and -219 Engines
(j) For JT8D-217C and -219 engines, perform the initial torque
inspection of 4th stage LPT blades for shroud notch wear. Use the
procedures described in Accomplishment Instructions, Part 2,
Paragraphs 1. through 3. of PW ASB No. JT8D A6224, Revision 5, dated
June 11, 2004, at the applicable threshold in the following Table 4:
Table 4.--Initial Torque Inspection Threshold for JT8D-217C and -219 Engines
----------------------------------------------------------------------------------------------------------------
Blade Type TIS Inspection threshold
----------------------------------------------------------------------------------------------------------------
(1) New pre-SB No. 6090 (small notch) Any number................................. Within 5,000 hours TIS.
4th stage turbine blades.
(2) Refurbished pre-SB No. 6090 (i) Fewer than 3,000....................... Within 4,000 hours TIS.
(small notch) 4th stage turbine
blades.
(ii) 3,000 or more......................... Within 5,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
(3) New post-SB No. 6090, new post-SB Any number................................. Within 10,000 hours TIS.
No. 6402, or new post-SB No. 6412
(large notch) 4th stage turbine
blades.
(4) Refurbished ``As-Cast'' post-SB Any number................................. Within 7,000 hours TIS.
No. 6090, post-SB No. 6402, or post-
SB No. 6412 (large notch) 4th stage
turbine blades.
(5) Refurbished ``Modified'' post-SB (i) Fewer than 3,000....................... Within 4,000 hours TIS.
No. 6090, post-SB No. 6402, or post-
SB No. 6412 (large notch) 4th stage
turbine blades.
(ii) 3,000 or more......................... Within 7,000 hours TIS, or
within 1,000 hours TIS
after the effective date of
this AD, whichever occurs
first.
----------------------------------------------------------------------------------------------------------------
Repetitive Torque Inspections for JT8D-217C and -219 Engines
(k) For JT8D-217C and -219 engines, perform repetitive torque
inspections of 4th stage LPT blades for shroud notch wear. Use the
procedures described in Accomplishment Instructions, Part 2,
Paragraph 1. of PW ASB No. JT8D A6224, Revision 5, dated June 11,
2004, at the applicable intervals in the following Table 5:
Table 5.--Repetitive Torque Inspection Intervals for JT8D-217C and -219 Engines
----------------------------------------------------------------------------------------------------------------
Inspection torque readings Number of readings Disposition
----------------------------------------------------------------------------------------------------------------
Greater than or equal to 15 LB-IN All........................................ Repeat torque inspection
(1.695 N.m). within 1,000 hours TIS
since last inspection.
Less than 15 LB-IN (1.695 N.m) but One or more................................ Repeat torque inspection
greater than or equal to 10 LB-IN within 500 hours TIS since
(1.130 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but One to six................................. Repeat torque inspection
greater than or equal to 5 LB-IN within 125 hours TIS since
(0.565 N.m). last inspection.
Less than 10 LB-IN (1.130 N.m) but Seven or more.............................. Remove engine from service
greater than or equal to 5 LB-IN within 20 hours TIS since
(0.565 N.m). last inspection.
Less than 5 LB-IN (0.565 N.m)........ One or more................................ Remove engine from service
within 20 hours TIS since
last inspection.
----------------------------------------------------------------------------------------------------------------
(l) Subsequent repeat inspection intervals must not exceed the
previous inspection interval.
JT8D-217C and -219 Engines Removed From Service
(m) JT8D-217C and -219 engines removed from service may be
returned to service after a detailed inspection and repair or
replacement for all blades, of the failed stage, that exceed Engine
Manual limits is done. Information on repairing or replacing turbine
blades can be found in Sections 72-53-12 through 72-53-13 of the
JT8D-200 Engine Manual, Part No. 773128.
Other Criteria for All Engine Models Listed in This AD
(n) Whenever a refurbished or used blade is intermixed with new
blades in a rotor, use the lowest initial inspection threshold that
is applicable.
(o) The initial torque inspection or the repetitive inspection
intervals for a particular stage may not be reset unless the blades
for that stage are refurbished or replaced.
(p) Whenever a used (service run) blade is reinstalled in a
rotor, the previous used time should be subtracted from the initial
torque inspection threshold.
LPT-to-Exhaust Case Bolts and Nuts Replacement
(q) At next accessibility to the LPT-to-exhaust case bolts, part
number (P/N) ST1315-15, and nuts, P/N 4023466, replace bolts and
nuts with bolts and nuts made of Tinidur material. Information on
replacing the bolts and nuts can be found in PW SB No. 6455, dated
January 15, 2004.
Definitions
(r) For the purpose of this AD, refurbishment is defined as
restoration of either the shrouds or blade retwist or both, per the
JT8D-200 Engine Manual, Part No. 773128.
(s) For the purpose of this AD, ``As-Cast'' refers to blades
that were machined from new castings and ``Modified'' refers to
blades that were derived from the pre-SB No. 6090 configuration.
(t) For the purpose of this AD, ``accessibility to the LPT-to-
exhaust case bolts'' refers to when the engine is disassembled
sufficiently to give access to the LPT-to-exhaust case bolts, which
is whenever the inner turbine fan ducts are removed.
[[Page 3871]]
Alternative Methods of Compliance
(u) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD if
requested using the procedures found in 14 CFR 39.19.
Material Incorporated by Reference
(v) You must use Pratt & Whitney (PW) Alert Service Bulletin
(ASB) No. JT8D A6224, Revision 5, dated June 11, 2004, to perform
the inspections required by this AD. The Director of the Federal
Register approved the incorporation by reference of this document in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a
copy from Pratt & Whitney, 400 Main St., East Hartford, CT 06108;
telephone (860) 565-8770, fax (860) 565-4503. You can review copies
at the FAA, New England Region, Office of the Regional Counsel, 12
New England Executive Park, Burlington, MA; or at the National
Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202-741-6030, or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
Related Information
(w) None.
Issued in Burlington, Massachusetts, on January 14, 2005.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 05-1463 Filed 1-26-05; 8:45 am]
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